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gstreamer/gst/gstpad.h
Sebastian Dröge d7f59ca0c4 pad: Deprecate GST_FLOW_IS_FATAL() and GST_FLOW_IS_SUCCESS() 
The problem with both macros is, that they suggest something that isn't true.
If GST_FLOW_IS_FATAL is true, there could still be a problem for many elements
and they should stop what they're currently doing and return that value
upstream (e.g. not-linked in a parser). If GST_FLOW_IS_SUCCESS is false, it
could still be that this is "ok" for the element (e.g. not-linked for a demuxer
on a few of its pads but not all).

It's better to not have these "convenience" macros but instead let people
*think* about the handling of different flow returns, that makes sense for
their element. And we should document the expected handling of flow returns for
different classes of elements in the plugin writer's guide.

Fixes bug #628014.
2010-08-27 16:59:08 +02:00

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wim.taymans@chello.be>
*
* gstpad.h: Header for GstPad object
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __GST_PAD_H__
#define __GST_PAD_H__
#include <gst/gstconfig.h>
#include <gst/gstobject.h>
#include <gst/gstbuffer.h>
#include <gst/gstbufferlist.h>
#include <gst/gstcaps.h>
#include <gst/gstevent.h>
#include <gst/gstquery.h>
#include <gst/gsttask.h>
G_BEGIN_DECLS
/*
* Pad base class
*/
#define GST_TYPE_PAD (gst_pad_get_type ())
#define GST_IS_PAD(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_PAD))
#define GST_IS_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_PAD))
#define GST_PAD(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_PAD, GstPad))
#define GST_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_PAD, GstPadClass))
#define GST_PAD_CAST(obj) ((GstPad*)(obj))
typedef struct _GstPad GstPad;
typedef struct _GstPadPrivate GstPadPrivate;
typedef struct _GstPadClass GstPadClass;
/**
* GstPadLinkReturn:
* @GST_PAD_LINK_OK : link succeeded
* @GST_PAD_LINK_WRONG_HIERARCHY: pads have no common grandparent
* @GST_PAD_LINK_WAS_LINKED : pad was already linked
* @GST_PAD_LINK_WRONG_DIRECTION: pads have wrong direction
* @GST_PAD_LINK_NOFORMAT : pads do not have common format
* @GST_PAD_LINK_NOSCHED : pads cannot cooperate in scheduling
* @GST_PAD_LINK_REFUSED : refused for some reason
*
* Result values from gst_pad_link and friends.
*/
typedef enum {
GST_PAD_LINK_OK = 0,
GST_PAD_LINK_WRONG_HIERARCHY = -1,
GST_PAD_LINK_WAS_LINKED = -2,
GST_PAD_LINK_WRONG_DIRECTION = -3,
GST_PAD_LINK_NOFORMAT = -4,
GST_PAD_LINK_NOSCHED = -5,
GST_PAD_LINK_REFUSED = -6
} GstPadLinkReturn;
/**
* GST_PAD_LINK_FAILED:
* @ret: the #GstPadLinkReturn value
*
* Macro to test if the given #GstPadLinkReturn value indicates a failed
* link step.
*/
#define GST_PAD_LINK_FAILED(ret) ((ret) < GST_PAD_LINK_OK)
/**
* GST_PAD_LINK_SUCCESSFUL:
* @ret: the #GstPadLinkReturn value
*
* Macro to test if the given #GstPadLinkReturn value indicates a successful
* link step.
*/
#define GST_PAD_LINK_SUCCESSFUL(ret) ((ret) >= GST_PAD_LINK_OK)
/**
* GstFlowReturn:
* @GST_FLOW_RESEND: Resend buffer, possibly with new caps (not
* sent yet) (unused/unimplemented).
* @GST_FLOW_OK: Data passing was ok.
* @GST_FLOW_NOT_LINKED: Pad is not linked.
* @GST_FLOW_WRONG_STATE: Pad is in wrong state.
* @GST_FLOW_UNEXPECTED: Did not expect anything, like after EOS.
* @GST_FLOW_NOT_NEGOTIATED: Pad is not negotiated.
* @GST_FLOW_ERROR: Some (fatal) error occured. Element generating
* this error should post an error message with more
* details.
* @GST_FLOW_NOT_SUPPORTED: This operation is not supported.
* @GST_FLOW_CUSTOM_SUCCESS: Elements can use values starting from
* this (and higher) to define custom success
* codes. Since 0.10.7.
* @GST_FLOW_CUSTOM_SUCCESS_1: Pre-defined custom success code (define your
* custom success code to this to avoid compiler
* warnings). Since 0.10.29.
* @GST_FLOW_CUSTOM_SUCCESS_2: Pre-defined custom success code. Since 0.10.29.
* @GST_FLOW_CUSTOM_ERROR: Elements can use values starting from
* this (and lower) to define custom error codes.
* Since 0.10.7.
* @GST_FLOW_CUSTOM_ERROR_1: Pre-defined custom error code (define your
* custom error code to this to avoid compiler
* warnings). Since 0.10.29.
* @GST_FLOW_CUSTOM_ERROR_2: Pre-defined custom error code. Since 0.10.29.
*
* The result of passing data to a pad.
*
* Note that the custom return values should not be exposed outside of the
* element scope and are available since 0.10.7.
*/
/* FIXME 0.11: remove custom flow returns */
typedef enum {
/* custom success starts here */
GST_FLOW_CUSTOM_SUCCESS_2 = 102,
GST_FLOW_CUSTOM_SUCCESS_1 = 101,
GST_FLOW_CUSTOM_SUCCESS = 100,
/* core predefined */
GST_FLOW_RESEND = 1,
GST_FLOW_OK = 0,
/* expected failures */
GST_FLOW_NOT_LINKED = -1,
GST_FLOW_WRONG_STATE = -2,
/* error cases */
GST_FLOW_UNEXPECTED = -3,
GST_FLOW_NOT_NEGOTIATED = -4,
GST_FLOW_ERROR = -5,
GST_FLOW_NOT_SUPPORTED = -6,
/* custom error starts here */
GST_FLOW_CUSTOM_ERROR = -100,
GST_FLOW_CUSTOM_ERROR_1 = -101,
GST_FLOW_CUSTOM_ERROR_2 = -102
} GstFlowReturn;
/**
* GST_FLOW_IS_FATAL:
* @ret: a #GstFlowReturn value
*
* Macro to test if the given #GstFlowReturn value indicates a fatal
* error. This macro is mainly used in elements driving the pipeline to decide
* whether an error message should be posted on the bus. Note that such
* elements may also need to post an error message in the #GST_FLOW_NOT_LINKED
* case which is not caught by this macro.
*
* Deprecated: This macro is badly named and can't be used in any real
* scenarios without additional checks.
*/
#ifndef GST_DISABLE_DEPRECATED
#define GST_FLOW_IS_FATAL(ret) ((ret) <= GST_FLOW_UNEXPECTED)
#endif
/**
* GST_FLOW_IS_SUCCESS:
* @ret: a #GstFlowReturn value
*
* Macro to test if the given #GstFlowReturn value indicates a
* successfull result
* This macro is mainly used in elements to decide if the processing
* of a buffer was successfull.
*
* Since: 0.10.7
*
* Deprecated: This macro is badly named and can't be used in any real
* scenarios without additional checks.
*/
#ifndef GST_DISABLE_DEPRECATED
#define GST_FLOW_IS_SUCCESS(ret) ((ret) >= GST_FLOW_OK)
#endif
G_CONST_RETURN gchar* gst_flow_get_name (GstFlowReturn ret);
GQuark gst_flow_to_quark (GstFlowReturn ret);
/**
* GstPadLinkCheck:
* @GST_PAD_LINK_CHECK_NOTHING: Don't check hierarchy or caps compatibility.
* @GST_PAD_LINK_CHECK_HIERARCHY: Check the pads have same parents/grandparents.
* Could be omitted if it is already known that the two elements that own the
* pads are in the same bin.
* @GST_PAD_LINK_CHECK_TEMPLATE_CAPS: Check if the pads are compatible by using
* their template caps. This is much faster than @GST_PAD_LINK_CHECK_CAPS, but
* would be unsafe e.g. if one pad has %GST_CAPS_ANY.
* @GST_PAD_LINK_CHECK_CAPS: Check if the pads are compatible by comparing the
* caps returned by gst_pad_get_caps().
*
* The amount of checking to be done when linking pads. @GST_PAD_LINK_CHECK_CAPS
* and @GST_PAD_LINK_CHECK_TEMPLATE_CAPS are mutually exclusive. If both are
* specified, expensive but safe @GST_PAD_LINK_CHECK_CAPS are performed.
*
* <warning><para>
* Only disable some of the checks if you are 100% certain you know the link
* will not fail because of hierarchy/caps compatibility failures. If uncertain,
* use the default checks (%GST_PAD_LINK_CHECK_DEFAULT) or the regular methods
* for linking the pads.
* </para></warning>
*
* Since: 0.10.30
*/
typedef enum {
GST_PAD_LINK_CHECK_NOTHING = 0,
GST_PAD_LINK_CHECK_HIERARCHY = 1 << 0,
GST_PAD_LINK_CHECK_TEMPLATE_CAPS = 1 << 1,
GST_PAD_LINK_CHECK_CAPS = 1 << 2
} GstPadLinkCheck;
/**
* GST_PAD_LINK_CHECK_DEFAULT:
*
* The default checks done when linking pads (i.e. the ones used by
* gst_pad_link()).
*
* Since: 0.10.30
*/
#define GST_PAD_LINK_CHECK_DEFAULT (GST_PAD_LINK_CHECK_HIERARCHY | GST_PAD_LINK_CHECK_CAPS)
/**
* GstActivateMode:
* @GST_ACTIVATE_NONE: Pad will not handle dataflow
* @GST_ACTIVATE_PUSH: Pad handles dataflow in downstream push mode
* @GST_ACTIVATE_PULL: Pad handles dataflow in upstream pull mode
*
* The status of a GstPad. After activating a pad, which usually happens when the
* parent element goes from READY to PAUSED, the GstActivateMode defines if the
* pad operates in push or pull mode.
*/
typedef enum {
GST_ACTIVATE_NONE,
GST_ACTIVATE_PUSH,
GST_ACTIVATE_PULL
} GstActivateMode;
/**
* GST_PAD_MODE_ACTIVATE:
* @mode: a #GstActivateMode
*
* Macro to test if the given #GstActivateMode value indicates that datapassing
* is possible or not.
*/
#define GST_PAD_MODE_ACTIVATE(mode) ((mode) != GST_ACTIVATE_NONE)
/* pad states */
/**
* GstPadActivateFunction:
* @pad: a #GstPad
*
* This function is called when the pad is activated during the element
* READY to PAUSED state change. By default this function will call the
* activate function that puts the pad in push mode but elements can
* override this function to activate the pad in pull mode if they wish.
*
* Returns: TRUE if the pad could be activated.
*/
typedef gboolean (*GstPadActivateFunction) (GstPad *pad);
/**
* GstPadActivateModeFunction:
* @pad: a #GstPad
* @active: activate or deactivate the pad.
*
* The prototype of the push and pull activate functions.
*
* Returns: TRUE if the pad could be activated or deactivated.
*/
typedef gboolean (*GstPadActivateModeFunction) (GstPad *pad, gboolean active);
/* data passing */
/**
* GstPadChainFunction:
* @pad: the sink #GstPad that performed the chain.
* @buffer: the #GstBuffer that is chained, not %NULL.
*
* A function that will be called on sinkpads when chaining buffers.
* The function typically processes the data contained in the buffer and
* either consumes the data or passes it on to the internally linked pad(s).
*
* The implementer of this function receives a refcount to @buffer and should
* gst_buffer_unref() when the buffer is no longer needed.
*
* When a chain function detects an error in the data stream, it must post an
* error on the bus and return an appropriate #GstFlowReturn value.
*
* Returns: #GST_FLOW_OK for success
*/
typedef GstFlowReturn (*GstPadChainFunction) (GstPad *pad, GstBuffer *buffer);
/**
* GstPadChainListFunction:
* @pad: the sink #GstPad that performed the chain.
* @list: the #GstBufferList that is chained, not %NULL.
*
* A function that will be called on sinkpads when chaining buffer lists.
* The function typically processes the data contained in the buffer list and
* either consumes the data or passes it on to the internally linked pad(s).
*
* The implementer of this function receives a refcount to @list and
* should gst_buffer_list_unref() when the list is no longer needed.
*
* When a chainlist function detects an error in the data stream, it must
* post an error on the bus and return an appropriate #GstFlowReturn value.
*
* Returns: #GST_FLOW_OK for success
*/
typedef GstFlowReturn (*GstPadChainListFunction) (GstPad *pad, GstBufferList *list);
/**
* GstPadGetRangeFunction:
* @pad: the src #GstPad to perform the getrange on.
* @offset: the offset of the range
* @length: the length of the range
* @buffer: a memory location to hold the result buffer, cannot be NULL.
*
* This function will be called on source pads when a peer element
* request a buffer at the specified @offset and @length. If this function
* returns #GST_FLOW_OK, the result buffer will be stored in @buffer. The
* contents of @buffer is invalid for any other return value.
*
* This function is installed on a source pad with
* gst_pad_set_getrange_function() and can only be called on source pads after
* they are successfully activated with gst_pad_activate_pull().
*
* @offset and @length are always given in byte units. @offset must normally be a value
* between 0 and the length in bytes of the data available on @pad. The
* length (duration in bytes) can be retrieved with a #GST_QUERY_DURATION or with a
* #GST_QUERY_SEEKING.
*
* Any @offset larger or equal than the length will make the function return
* #GST_FLOW_UNEXPECTED, which corresponds to EOS. In this case @buffer does not
* contain a valid buffer.
*
* The buffer size of @buffer will only be smaller than @length when @offset is
* near the end of the stream. In all other cases, the size of @buffer must be
* exactly the requested size.
*
* It is allowed to call this function with a 0 @length and valid @offset, in
* which case @buffer will contain a 0-sized buffer and the function returns
* #GST_FLOW_OK.
*
* When this function is called with a -1 @offset, the sequentially next buffer
* of length @length in the stream is returned.
*
* When this function is called with a -1 @length, a buffer with a default
* optimal length is returned in @buffer. The length might depend on the value
* of @offset.
*
* Returns: #GST_FLOW_OK for success and a valid buffer in @buffer. Any other
* return value leaves @buffer undefined.
*/
typedef GstFlowReturn (*GstPadGetRangeFunction) (GstPad *pad, guint64 offset,
guint length, GstBuffer **buffer);
/**
* GstPadEventFunction:
* @pad: the #GstPad to handle the event.
* @event: the #GstEvent to handle.
*
* Function signature to handle an event for the pad.
*
* Returns: TRUE if the pad could handle the event.
*/
typedef gboolean (*GstPadEventFunction) (GstPad *pad, GstEvent *event);
/* FIXME: 0.11: deprecate me, check range should use seeking query */
/**
* GstPadCheckGetRangeFunction:
* @pad: a #GstPad
*
* Check if @pad can be activated in pull mode.
*
* This function will be deprecated after 0.10; use the seeking query to check
* if a pad can support random access.
*
* Returns: TRUE if the pad can operate in pull mode.
*/
typedef gboolean (*GstPadCheckGetRangeFunction) (GstPad *pad);
/* internal links */
/**
* GstPadIntLinkFunction:
* @pad: The #GstPad to query.
*
* The signature of the internal pad link function.
*
* Returns: (element-type Gst.Pad) (transfer container): a newly allocated #GList of pads that are linked to the given pad on
* the inside of the parent element.
*
* The caller must call g_list_free() on it after use.
*
* Deprecated: use the threadsafe #GstPadIterIntLinkFunction instead.
*/
typedef GList* (*GstPadIntLinkFunction) (GstPad *pad);
/**
* GstPadIterIntLinkFunction:
* @pad: The #GstPad to query.
*
* The signature of the internal pad link iterator function.
*
* Returns: a new #GstIterator that will iterate over all pads that are
* linked to the given pad on the inside of the parent element.
*
* the caller must call gst_iterator_free() after usage.
*
* Since 0.10.21
*/
typedef GstIterator* (*GstPadIterIntLinkFunction) (GstPad *pad);
/* generic query function */
/**
* GstPadQueryTypeFunction:
* @pad: a #GstPad to query
*
* The signature of the query types function.
*
* Returns: a constant array of query types
*/
typedef const GstQueryType* (*GstPadQueryTypeFunction) (GstPad *pad);
/**
* GstPadQueryFunction:
* @pad: the #GstPad to query.
* @query: the #GstQuery object to execute
*
* The signature of the query function.
*
* Returns: TRUE if the query could be performed.
*/
typedef gboolean (*GstPadQueryFunction) (GstPad *pad, GstQuery *query);
/* linking */
/**
* GstPadLinkFunction
* @pad: the #GstPad that is linked.
* @peer: the peer #GstPad of the link
*
* Function signature to handle a new link on the pad.
*
* Returns: the result of the link with the specified peer.
*/
typedef GstPadLinkReturn (*GstPadLinkFunction) (GstPad *pad, GstPad *peer);
/**
* GstPadUnlinkFunction
* @pad: the #GstPad that is linked.
*
* Function signature to handle a unlinking the pad prom its peer.
*/
typedef void (*GstPadUnlinkFunction) (GstPad *pad);
/* caps nego */
/**
* GstPadGetCapsFunction:
* @pad: the #GstPad to get the capabilities of.
*
* Returns a copy of the capabilities of the specified pad. By default this
* function will return the pad template capabilities, but can optionally
* be overridden by elements.
*
* Returns: a newly allocated copy #GstCaps of the pad.
*/
typedef GstCaps* (*GstPadGetCapsFunction) (GstPad *pad);
/**
* GstPadSetCapsFunction:
* @pad: the #GstPad to set the capabilities of.
* @caps: the #GstCaps to set
*
* Set @caps on @pad. By default this function updates the caps of the
* pad but the function can be overriden by elements to perform extra
* actions or verifications.
*
* Returns: TRUE if the caps could be set on the pad.
*/
typedef gboolean (*GstPadSetCapsFunction) (GstPad *pad, GstCaps *caps);
/**
* GstPadAcceptCapsFunction:
* @pad: the #GstPad to check
* @caps: the #GstCaps to check
*
* Check if @pad can accept @caps. By default this function will see if @caps
* intersect with the result from gst_pad_get_caps() by can be overridden to
* perform extra checks.
*
* Returns: TRUE if the caps can be accepted by the pad.
*/
typedef gboolean (*GstPadAcceptCapsFunction) (GstPad *pad, GstCaps *caps);
/**
* GstPadFixateCapsFunction:
* @pad: a #GstPad
* @caps: the #GstCaps to fixate
*
* Given possibly unfixed caps @caps, let @pad use its default prefered
* format to make a fixed caps. @caps should be writable. By default this
* function will pick the first value of any ranges or lists in the caps but
* elements can override this function to perform other behaviour.
*/
typedef void (*GstPadFixateCapsFunction) (GstPad *pad, GstCaps *caps);
/**
* GstPadBufferAllocFunction:
* @pad: a sink #GstPad
* @offset: the desired offset of the buffer
* @size: the desired size of the buffer
* @caps: the desired caps of the buffer
* @buf: pointer to hold the allocated buffer.
*
* Ask the sinkpad @pad to allocate a buffer with @offset, @size and @caps.
* The result will be stored in @buf.
*
* The purpose of this function is to allocate a buffer that is optimal to
* be processed by @pad. The function is mostly overridden by elements that can
* provide a hardware buffer in order to avoid additional memcpy operations.
*
* The function can return a buffer that has caps different from the requested
* @caps, in which case the upstream element requests a format change to this
* new caps.
* If a format change was requested, the returned buffer will be one to hold
* the data of said new caps, so its size might be different from the requested
* @size.
*
* When this function returns anything else than #GST_FLOW_OK, the buffer allocation
* failed and @buf does not contain valid data. If the function returns #GST_FLOW_OK and
* the @buf is NULL, a #GstBuffer will be created with @caps, @offset and @size.
*
* By default this function returns a new buffer of @size and with @caps containing
* purely malloced data. The buffer should be freed with gst_buffer_unref()
* after usage.
*
* Returns: #GST_FLOW_OK if @buf contains a valid buffer, any other return
* value means @buf does not hold a valid buffer.
*/
typedef GstFlowReturn (*GstPadBufferAllocFunction) (GstPad *pad, guint64 offset, guint size,
GstCaps *caps, GstBuffer **buf);
/* misc */
/**
* GstPadDispatcherFunction:
* @pad: the #GstPad that is dispatched.
* @data: the gpointer to optional user data.
*
* A dispatcher function is called for all internally linked pads, see
* gst_pad_dispatcher().
*
* Returns: TRUE if the dispatching procedure has to be stopped.
*/
typedef gboolean (*GstPadDispatcherFunction) (GstPad *pad, gpointer data);
/**
* GstPadBlockCallback:
* @pad: the #GstPad that is blockend or unblocked.
* @blocked: blocking state for the pad
* @user_data: the gpointer to optional user data.
*
* Callback used by gst_pad_set_blocked_async(). Gets called when the blocking
* operation succeeds.
*/
typedef void (*GstPadBlockCallback) (GstPad *pad, gboolean blocked, gpointer user_data);
/**
* GstPadDirection:
* @GST_PAD_UNKNOWN: direction is unknown.
* @GST_PAD_SRC: the pad is a source pad.
* @GST_PAD_SINK: the pad is a sink pad.
*
* The direction of a pad.
*/
typedef enum {
GST_PAD_UNKNOWN,
GST_PAD_SRC,
GST_PAD_SINK
} GstPadDirection;
/**
* GstPadFlags:
* @GST_PAD_BLOCKED: is dataflow on a pad blocked
* @GST_PAD_FLUSHING: is pad refusing buffers
* @GST_PAD_IN_GETCAPS: GstPadGetCapsFunction() is running now
* @GST_PAD_IN_SETCAPS: GstPadSetCapsFunction() is running now
* @GST_PAD_BLOCKING: is pad currently blocking on a buffer or event
* @GST_PAD_FLAG_LAST: offset to define more flags
*
* Pad state flags
*/
typedef enum {
GST_PAD_BLOCKED = (GST_OBJECT_FLAG_LAST << 0),
GST_PAD_FLUSHING = (GST_OBJECT_FLAG_LAST << 1),
GST_PAD_IN_GETCAPS = (GST_OBJECT_FLAG_LAST << 2),
GST_PAD_IN_SETCAPS = (GST_OBJECT_FLAG_LAST << 3),
GST_PAD_BLOCKING = (GST_OBJECT_FLAG_LAST << 4),
/* padding */
GST_PAD_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 8)
} GstPadFlags;
/* FIXME: this awful circular dependency need to be resolved properly (see padtemplate.h) */
typedef struct _GstPadTemplate GstPadTemplate;
/**
* GstPad:
* @element_private: private data owned by the parent element
* @padtemplate: padtemplate for this pad
* @direction: the direction of the pad, cannot change after creating
* the pad.
* @stream_rec_lock: recursive stream lock of the pad, used to protect
* the data used in streaming.
* @task: task for this pad if the pad is actively driving dataflow.
* @preroll_lock: lock used when prerolling
* @preroll_cond: conf to signal preroll
* @block_cond: conditional to signal pad block
* @block_callback: callback for the pad block if any
* @block_data: user data for @block_callback
* @caps: the current caps of the pad
* @getcapsfunc: function to get caps of the pad
* @setcapsfunc: function to set caps on the pad
* @acceptcapsfunc: function to check if pad can accept caps
* @fixatecapsfunc: function to fixate caps
* @activatefunc: pad activation function
* @activatepushfunc: function to activate/deactivate pad in push mode
* @activatepullfunc: function to activate/deactivate pad in pull mode
* @linkfunc: function called when pad is linked
* @unlinkfunc: function called when pad is unlinked
* @peer: the pad this pad is linked to
* @sched_private: private storage for the scheduler
* @chainfunc: function to chain buffer to pad
* @checkgetrangefunc: function to check if pad can operate in pull mode
* @getrangefunc: function to get a range of data from a pad
* @eventfunc: function to send an event to a pad
* @mode: current activation mode of the pad
* @querytypefunc: get list of supported queries
* @queryfunc: perform a query on the pad
* @intlinkfunc: get the internal links of this pad
* @bufferallocfunc: function to allocate a buffer for this pad
* @do_buffer_signals: counter counting installed buffer signals
* @do_event_signals: counter counting installed event signals
* @iterintlinkfunc: get the internal links iterator of this pad
* @block_destroy_data: notify function for gst_pad_set_blocked_async_full()
*
* The #GstPad structure. Use the functions to update the variables.
*/
struct _GstPad {
GstObject object;
/*< public >*/
gpointer element_private;
GstPadTemplate *padtemplate;
GstPadDirection direction;
/*< public >*/ /* with STREAM_LOCK */
/* streaming rec_lock */
GStaticRecMutex *stream_rec_lock;
GstTask *task;
/*< public >*/ /* with PREROLL_LOCK */
GMutex *preroll_lock;
GCond *preroll_cond;
/*< public >*/ /* with LOCK */
/* block cond, mutex is from the object */
GCond *block_cond;
GstPadBlockCallback block_callback;
gpointer block_data;
/* the pad capabilities */
GstCaps *caps;
GstPadGetCapsFunction getcapsfunc;
GstPadSetCapsFunction setcapsfunc;
GstPadAcceptCapsFunction acceptcapsfunc;
GstPadFixateCapsFunction fixatecapsfunc;
GstPadActivateFunction activatefunc;
GstPadActivateModeFunction activatepushfunc;
GstPadActivateModeFunction activatepullfunc;
/* pad link */
GstPadLinkFunction linkfunc;
GstPadUnlinkFunction unlinkfunc;
GstPad *peer;
gpointer sched_private;
/* data transport functions */
GstPadChainFunction chainfunc;
GstPadCheckGetRangeFunction checkgetrangefunc;
GstPadGetRangeFunction getrangefunc;
GstPadEventFunction eventfunc;
GstActivateMode mode;
/* generic query method */
GstPadQueryTypeFunction querytypefunc;
GstPadQueryFunction queryfunc;
/* internal links */
GstPadIntLinkFunction intlinkfunc;
GstPadBufferAllocFunction bufferallocfunc;
/* whether to emit signals for have-data. counts number
* of handlers attached. */
gint do_buffer_signals;
gint do_event_signals;
/* ABI added */
/* iterate internal links */
GstPadIterIntLinkFunction iterintlinkfunc;
/* free block_data */
GDestroyNotify block_destroy_data;
/*< private >*/
union {
struct {
gboolean block_callback_called;
GstPadPrivate *priv;
} ABI;
gpointer _gst_reserved[GST_PADDING - 2];
} abidata;
};
struct _GstPadClass {
GstObjectClass parent_class;
/* signal callbacks */
void (*linked) (GstPad *pad, GstPad *peer);
void (*unlinked) (GstPad *pad, GstPad *peer);
void (*request_link) (GstPad *pad);
gboolean (*have_data) (GstPad *pad, GstMiniObject *data);
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
/***** helper macros *****/
/* GstPad */
#define GST_PAD_NAME(pad) (GST_OBJECT_NAME(pad))
#define GST_PAD_PARENT(pad) (GST_ELEMENT_CAST(GST_OBJECT_PARENT(pad)))
#define GST_PAD_ELEMENT_PRIVATE(pad) (GST_PAD_CAST(pad)->element_private)
#define GST_PAD_PAD_TEMPLATE(pad) (GST_PAD_CAST(pad)->padtemplate)
#define GST_PAD_DIRECTION(pad) (GST_PAD_CAST(pad)->direction)
#define GST_PAD_TASK(pad) (GST_PAD_CAST(pad)->task)
#define GST_PAD_ACTIVATE_MODE(pad) (GST_PAD_CAST(pad)->mode)
#define GST_PAD_ACTIVATEFUNC(pad) (GST_PAD_CAST(pad)->activatefunc)
#define GST_PAD_ACTIVATEPUSHFUNC(pad) (GST_PAD_CAST(pad)->activatepushfunc)
#define GST_PAD_ACTIVATEPULLFUNC(pad) (GST_PAD_CAST(pad)->activatepullfunc)
#define GST_PAD_CHAINFUNC(pad) (GST_PAD_CAST(pad)->chainfunc)
#define GST_PAD_CHECKGETRANGEFUNC(pad) (GST_PAD_CAST(pad)->checkgetrangefunc)
#define GST_PAD_GETRANGEFUNC(pad) (GST_PAD_CAST(pad)->getrangefunc)
#define GST_PAD_EVENTFUNC(pad) (GST_PAD_CAST(pad)->eventfunc)
#define GST_PAD_QUERYTYPEFUNC(pad) (GST_PAD_CAST(pad)->querytypefunc)
#define GST_PAD_QUERYFUNC(pad) (GST_PAD_CAST(pad)->queryfunc)
#ifndef GST_DISABLE_DEPRECATED
#define GST_PAD_INTLINKFUNC(pad) (GST_PAD_CAST(pad)->intlinkfunc)
#endif
#define GST_PAD_ITERINTLINKFUNC(pad) (GST_PAD_CAST(pad)->iterintlinkfunc)
#define GST_PAD_PEER(pad) (GST_PAD_CAST(pad)->peer)
#define GST_PAD_LINKFUNC(pad) (GST_PAD_CAST(pad)->linkfunc)
#define GST_PAD_UNLINKFUNC(pad) (GST_PAD_CAST(pad)->unlinkfunc)
/**
* GST_PAD_CAPS:
* @pad: a #GstPad.
*
* The caps for this pad.
*/
#define GST_PAD_CAPS(pad) (GST_PAD_CAST(pad)->caps)
#define GST_PAD_GETCAPSFUNC(pad) (GST_PAD_CAST(pad)->getcapsfunc)
#define GST_PAD_SETCAPSFUNC(pad) (GST_PAD_CAST(pad)->setcapsfunc)
#define GST_PAD_ACCEPTCAPSFUNC(pad) (GST_PAD_CAST(pad)->acceptcapsfunc)
#define GST_PAD_FIXATECAPSFUNC(pad) (GST_PAD_CAST(pad)->fixatecapsfunc)
#define GST_PAD_BUFFERALLOCFUNC(pad) (GST_PAD_CAST(pad)->bufferallocfunc)
#define GST_PAD_DO_BUFFER_SIGNALS(pad) (GST_PAD_CAST(pad)->do_buffer_signals)
#define GST_PAD_DO_EVENT_SIGNALS(pad) (GST_PAD_CAST(pad)->do_event_signals)
#define GST_PAD_IS_LINKED(pad) (GST_PAD_PEER(pad) != NULL)
#define GST_PAD_IS_BLOCKED(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKED))
#define GST_PAD_IS_BLOCKING(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_BLOCKING))
#define GST_PAD_IS_FLUSHING(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_FLUSHING))
#define GST_PAD_IS_IN_GETCAPS(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_IN_GETCAPS))
#define GST_PAD_IS_IN_SETCAPS(pad) (GST_OBJECT_FLAG_IS_SET (pad, GST_PAD_IN_SETCAPS))
#define GST_PAD_IS_SRC(pad) (GST_PAD_DIRECTION(pad) == GST_PAD_SRC)
#define GST_PAD_IS_SINK(pad) (GST_PAD_DIRECTION(pad) == GST_PAD_SINK)
#define GST_PAD_SET_FLUSHING(pad) (GST_OBJECT_FLAG_SET (pad, GST_PAD_FLUSHING))
#define GST_PAD_UNSET_FLUSHING(pad) (GST_OBJECT_FLAG_UNSET (pad, GST_PAD_FLUSHING))
/**
* GST_PAD_GET_STREAM_LOCK:
* @pad: a #GstPad
*
* Get the stream lock of @pad. The stream lock is protecting the
* resources used in the data processing functions of @pad.
*/
#define GST_PAD_GET_STREAM_LOCK(pad) (GST_PAD_CAST(pad)->stream_rec_lock)
/**
* GST_PAD_STREAM_LOCK:
* @pad: a #GstPad
*
* Lock the stream lock of @pad.
*/
#define GST_PAD_STREAM_LOCK(pad) (g_static_rec_mutex_lock(GST_PAD_GET_STREAM_LOCK(pad)))
/**
* GST_PAD_STREAM_LOCK_FULL:
* @pad: a #GstPad
* @t: the number of times to recursively lock
*
* Lock the stream lock of @pad @t times.
*/
#define GST_PAD_STREAM_LOCK_FULL(pad,t) (g_static_rec_mutex_lock_full(GST_PAD_GET_STREAM_LOCK(pad), t))
/**
* GST_PAD_STREAM_TRYLOCK:
* @pad: a #GstPad
*
* Try to Lock the stream lock of the pad, return TRUE if the lock could be
* taken.
*/
#define GST_PAD_STREAM_TRYLOCK(pad) (g_static_rec_mutex_trylock(GST_PAD_GET_STREAM_LOCK(pad)))
/**
* GST_PAD_STREAM_UNLOCK:
* @pad: a #GstPad
*
* Unlock the stream lock of @pad.
*/
#define GST_PAD_STREAM_UNLOCK(pad) (g_static_rec_mutex_unlock(GST_PAD_GET_STREAM_LOCK(pad)))
/**
* GST_PAD_STREAM_UNLOCK_FULL:
* @pad: a #GstPad
*
* Fully unlock the recursive stream lock of @pad, return the number of times
* @pad was locked.
*/
#define GST_PAD_STREAM_UNLOCK_FULL(pad) (g_static_rec_mutex_unlock_full(GST_PAD_GET_STREAM_LOCK(pad)))
#define GST_PAD_GET_PREROLL_LOCK(pad) (GST_PAD_CAST(pad)->preroll_lock)
#define GST_PAD_PREROLL_LOCK(pad) (g_mutex_lock(GST_PAD_GET_PREROLL_LOCK(pad)))
#define GST_PAD_PREROLL_TRYLOCK(pad) (g_mutex_trylock(GST_PAD_GET_PREROLL_LOCK(pad)))
#define GST_PAD_PREROLL_UNLOCK(pad) (g_mutex_unlock(GST_PAD_GET_PREROLL_LOCK(pad)))
#define GST_PAD_GET_PREROLL_COND(pad) (GST_PAD_CAST(pad)->preroll_cond)
#define GST_PAD_PREROLL_WAIT(pad) \
g_cond_wait (GST_PAD_GET_PREROLL_COND (pad), GST_PAD_GET_PREROLL_LOCK (pad))
#define GST_PAD_PREROLL_TIMED_WAIT(pad, timeval) \
g_cond_timed_wait (GST_PAD_GET_PREROLL_COND (pad), GST_PAD_GET_PREROLL_LOCK (pad), timeval)
#define GST_PAD_PREROLL_SIGNAL(pad) g_cond_signal (GST_PAD_GET_PREROLL_COND (pad));
#define GST_PAD_PREROLL_BROADCAST(pad) g_cond_broadcast (GST_PAD_GET_PREROLL_COND (pad));
#define GST_PAD_BLOCK_GET_COND(pad) (GST_PAD_CAST(pad)->block_cond)
#define GST_PAD_BLOCK_WAIT(pad) (g_cond_wait(GST_PAD_BLOCK_GET_COND (pad), GST_OBJECT_GET_LOCK (pad)))
#define GST_PAD_BLOCK_SIGNAL(pad) (g_cond_signal(GST_PAD_BLOCK_GET_COND (pad)))
#define GST_PAD_BLOCK_BROADCAST(pad) (g_cond_broadcast(GST_PAD_BLOCK_GET_COND (pad)))
/* FIXME: this awful circular dependency need to be resolved properly (see padtemplate.h) */
#include <gst/gstpadtemplate.h>
GType gst_pad_get_type (void);
/* creating pads */
GstPad* gst_pad_new (const gchar *name, GstPadDirection direction);
GstPad* gst_pad_new_from_template (GstPadTemplate *templ, const gchar *name);
GstPad* gst_pad_new_from_static_template (GstStaticPadTemplate *templ, const gchar *name);
/**
* gst_pad_get_name:
* @pad: the pad to get the name from
*
* Get a copy of the name of the pad. g_free() after usage.
*
* MT safe.
*/
#define gst_pad_get_name(pad) gst_object_get_name (GST_OBJECT_CAST (pad))
/**
* gst_pad_get_parent:
* @pad: the pad to get the parent of
*
* Get the parent of @pad. This function increases the refcount
* of the parent object so you should gst_object_unref() it after usage.
* Can return NULL if the pad did not have a parent.
*
* MT safe.
*/
#define gst_pad_get_parent(pad) gst_object_get_parent (GST_OBJECT_CAST (pad))
GstPadDirection gst_pad_get_direction (GstPad *pad);
gboolean gst_pad_set_active (GstPad *pad, gboolean active);
gboolean gst_pad_is_active (GstPad *pad);
gboolean gst_pad_activate_pull (GstPad *pad, gboolean active);
gboolean gst_pad_activate_push (GstPad *pad, gboolean active);
gboolean gst_pad_set_blocked (GstPad *pad, gboolean blocked);
gboolean gst_pad_set_blocked_async (GstPad *pad, gboolean blocked,
GstPadBlockCallback callback, gpointer user_data);
gboolean gst_pad_set_blocked_async_full (GstPad *pad, gboolean blocked,
GstPadBlockCallback callback, gpointer user_data,
GDestroyNotify destroy_data);
gboolean gst_pad_is_blocked (GstPad *pad);
gboolean gst_pad_is_blocking (GstPad *pad);
void gst_pad_set_element_private (GstPad *pad, gpointer priv);
gpointer gst_pad_get_element_private (GstPad *pad);
GstPadTemplate* gst_pad_get_pad_template (GstPad *pad);
void gst_pad_set_bufferalloc_function (GstPad *pad, GstPadBufferAllocFunction bufalloc);
GstFlowReturn gst_pad_alloc_buffer (GstPad *pad, guint64 offset, gint size,
GstCaps *caps, GstBuffer **buf);
GstFlowReturn gst_pad_alloc_buffer_and_set_caps (GstPad *pad, guint64 offset, gint size,
GstCaps *caps, GstBuffer **buf);
/* data passing setup functions */
void gst_pad_set_activate_function (GstPad *pad, GstPadActivateFunction activate);
void gst_pad_set_activatepull_function (GstPad *pad, GstPadActivateModeFunction activatepull);
void gst_pad_set_activatepush_function (GstPad *pad, GstPadActivateModeFunction activatepush);
void gst_pad_set_chain_function (GstPad *pad, GstPadChainFunction chain);
void gst_pad_set_chain_list_function (GstPad *pad, GstPadChainListFunction chainlist);
void gst_pad_set_getrange_function (GstPad *pad, GstPadGetRangeFunction get);
void gst_pad_set_checkgetrange_function (GstPad *pad, GstPadCheckGetRangeFunction check);
void gst_pad_set_event_function (GstPad *pad, GstPadEventFunction event);
/* pad links */
void gst_pad_set_link_function (GstPad *pad, GstPadLinkFunction link);
void gst_pad_set_unlink_function (GstPad *pad, GstPadUnlinkFunction unlink);
gboolean gst_pad_can_link (GstPad *srcpad, GstPad *sinkpad);
GstPadLinkReturn gst_pad_link (GstPad *srcpad, GstPad *sinkpad);
GstPadLinkReturn gst_pad_link_full (GstPad *srcpad, GstPad *sinkpad, GstPadLinkCheck flags);
gboolean gst_pad_unlink (GstPad *srcpad, GstPad *sinkpad);
gboolean gst_pad_is_linked (GstPad *pad);
GstPad* gst_pad_get_peer (GstPad *pad);
/* capsnego functions */
void gst_pad_set_getcaps_function (GstPad *pad, GstPadGetCapsFunction getcaps);
void gst_pad_set_acceptcaps_function (GstPad *pad, GstPadAcceptCapsFunction acceptcaps);
void gst_pad_set_fixatecaps_function (GstPad *pad, GstPadFixateCapsFunction fixatecaps);
void gst_pad_set_setcaps_function (GstPad *pad, GstPadSetCapsFunction setcaps);
G_CONST_RETURN GstCaps* gst_pad_get_pad_template_caps (GstPad *pad);
/* capsnego function for linked/unlinked pads */
GstCaps * gst_pad_get_caps_reffed (GstPad * pad);
GstCaps * gst_pad_get_caps (GstPad * pad);
void gst_pad_fixate_caps (GstPad * pad, GstCaps *caps);
gboolean gst_pad_accept_caps (GstPad * pad, GstCaps *caps);
gboolean gst_pad_set_caps (GstPad * pad, GstCaps *caps);
GstCaps * gst_pad_peer_get_caps_reffed (GstPad * pad);
GstCaps * gst_pad_peer_get_caps (GstPad * pad);
gboolean gst_pad_peer_accept_caps (GstPad * pad, GstCaps *caps);
/* capsnego for linked pads */
GstCaps * gst_pad_get_allowed_caps (GstPad * pad);
GstCaps * gst_pad_get_negotiated_caps (GstPad * pad);
/* data passing functions to peer */
GstFlowReturn gst_pad_push (GstPad *pad, GstBuffer *buffer);
GstFlowReturn gst_pad_push_list (GstPad *pad, GstBufferList *list);
gboolean gst_pad_check_pull_range (GstPad *pad);
GstFlowReturn gst_pad_pull_range (GstPad *pad, guint64 offset, guint size,
GstBuffer **buffer);
gboolean gst_pad_push_event (GstPad *pad, GstEvent *event);
gboolean gst_pad_event_default (GstPad *pad, GstEvent *event);
/* data passing functions on pad */
GstFlowReturn gst_pad_chain (GstPad *pad, GstBuffer *buffer);
GstFlowReturn gst_pad_chain_list (GstPad *pad, GstBufferList *list);
GstFlowReturn gst_pad_get_range (GstPad *pad, guint64 offset, guint size,
GstBuffer **buffer);
gboolean gst_pad_send_event (GstPad *pad, GstEvent *event);
/* pad tasks */
gboolean gst_pad_start_task (GstPad *pad, GstTaskFunction func,
gpointer data);
gboolean gst_pad_pause_task (GstPad *pad);
gboolean gst_pad_stop_task (GstPad *pad);
/* internal links */
#ifndef GST_DISABLE_DEPRECATED
void gst_pad_set_internal_link_function (GstPad *pad, GstPadIntLinkFunction intlink);
GList* gst_pad_get_internal_links (GstPad *pad);
GList* gst_pad_get_internal_links_default (GstPad *pad);
#endif
void gst_pad_set_iterate_internal_links_function (GstPad * pad,
GstPadIterIntLinkFunction iterintlink);
GstIterator * gst_pad_iterate_internal_links (GstPad * pad);
GstIterator * gst_pad_iterate_internal_links_default (GstPad * pad);
/* generic query function */
void gst_pad_set_query_type_function (GstPad *pad, GstPadQueryTypeFunction type_func);
G_CONST_RETURN GstQueryType*
gst_pad_get_query_types (GstPad *pad);
G_CONST_RETURN GstQueryType*
gst_pad_get_query_types_default (GstPad *pad);
gboolean gst_pad_query (GstPad *pad, GstQuery *query);
gboolean gst_pad_peer_query (GstPad *pad, GstQuery *query);
void gst_pad_set_query_function (GstPad *pad, GstPadQueryFunction query);
gboolean gst_pad_query_default (GstPad *pad, GstQuery *query);
/* misc helper functions */
gboolean gst_pad_dispatcher (GstPad *pad, GstPadDispatcherFunction dispatch,
gpointer data);
#if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_DISABLE_DEPRECATED)
void gst_pad_load_and_link (xmlNodePtr self, GstObject *parent);
#endif
G_END_DECLS
#endif /* __GST_PAD_H__ */
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